Flash Floods, Top to Bottom: What We Did Right, Where It Went Wrong

Oops! Water is everywhere. From April to September, Dongguan, a city with mild subtropical weather, has entered its wet season, posing a challenge to Dongguan’s drainage system.

At the end of March, a downpour, although not a record high, caught Dongguan off guard. The storm hovered, water overflowed, cars were submerged, traffic was stranded, and a wave of fury followed, widely expressed on Weibo, China’s popular micro blogging site, as netizens kept posting pictures of flood damage and sharing critiques of an unsatisfactory drainage system and its management.

Moreover, during the flood, a 16-year-old girl in Liaobu and a middle-aged man in Changping were swept away to their deaths. The tragedy once again has prompted officials to reflect on the city management.

Crippling Events

On the evening of March 30, a thunderstorm hit Dongguan. In response the Dongguan Meteorology Bureau (DMB) kept the latest weather information updated on line. The two-day deluge brought the city an average precipitation of over 100 milimeter per day, and waist-deep flash floods.

On the following morning, students and parents, concerned with whether school would be suspended, had trouble confirming the schedule. At 7:11 a.m., the DMB issued an orange storm warning, but it took over an hour for the Dongguan Education Bureau (DEB) to respond. At 8:30, they unveiled their decision, “kindergarten and primary schools will suspend classes.”

Shortly after sending their children off to school, many had to return to pick them up. “The orange signal warning has already been issued, why can’t the educational department react a little bit earlier?” some parents said in discontent with a suspension notice criticized as slow and ambiguous.

Yuan Baocheng, mayor of Dongguan said during an emergency response drill on April 9 that, “we must radically solve the problem of flash flooding.”

In response of what netizens called “the most chilling” department, claiming that the DEM acted “too calmly” in the face of a severe thunderstorm, they admitted that their response suffered from “inexperience,” and would consider strengthening its cooperation with Dongguan’s meteorological departments and work harder to improve the mechanisms for the school suspension notice to comply with disaster prevention regulations already in place.

The flood also paralyzed public transportation, leaving many trapped in the rainstorm waiting unawares at bus stations. And the official Dongguan Government Weibo account, Guanxiang Huakai, advised that, “The water is deep and fast so the cars are very likely to become submerged, so drivers need to drive slowly with the utmost care.”

The account also pointed out areas around Dongguan that they marked as “Black Spots,” places prone to flood. “Drivers need to memorize some black spots for water draining. Stay away from those spots when it rains heavily,” it read.

It also warned that, in stormy conditions, drivers should not use cruise control, not cross running water and watch out for pedestrians.

Although the thunderstorm caused inconveniences for many, it was nothing at all when compared to the two lives lost in the flood. On March 30, a 16-year-old girl from Dongguan University of Technology in Liaobu Town lost her life in its prime. On her way home, she was washed into a sewer manhole without any protective measures or any warning sign. This terrifying tragedy also happened to another 51-year-old man in Changping on the same day.

The tragedies aroused the public awareness of the dangers existing in urban infrastructures, sparking an outcry for ensuring public security. After the deaths, a buffer belt was added to the drainage channels that swallowed two lives as a protected zone. “If the responsible had done it in advance, the deaths could have been avoided,” said a Weibo user, adding that nothing could be done to bring back the lost lives; the only thing was to learn the lesson.

“If a city cannot withstand the impact of a heavy rain, the department in charge of city management should be blamed,” said Meng Qiang to the Nanfang Daily as an expert from the Civil Law Research Association of China. “Because the manholes are in so many places, the authorities should maintain the well.”

Grading the Response

In the past decades, skyscrapers, infrastructure, roads, modern transportation networks and more have been built upon the grounds of Dongguan, but the recent heavy rains just washed out any underground weaknesses. Dongguan’s shortfalls in the emergency situations and the public fallout that followed have propelled top to bottom actions in search of remedies.

During search and rescue drills in early April, authorities practice recovering flood victims at the Dongguan Water Affairs Bureau. (Credit: Zhao Hanrui)

In April, a document regarding improvements for the drainage systems across the cities of Guangdong was released by the Guangdong Provincial Government requiring them, by the year 2017, to improve sewer drainage system of high water areas, to upgrade the distribution of rain and sewage design, to eliminate city water logging and to build up the platform for city drainage information management. Also, it requires prefecture level cities like Dongguan to establish drainage systems that can endure the impact of such storms within no more than 30 years.

The heads of Dongguan’s City Government, prompted by the public outcry, came out to show an emphasis on disaster precautions. Yuan Baocheng, mayor of Dongguan said during an emergency response drill on April 9, “we must radically solve the problem of flash flooding.” It should also be pointed out that, as he said in the announcement, that Dongguan has since 2009 invested a total of RMB 294.5 million on the City Water-logging Upgrading Project, which has led to the flash flood zones decreasing from 53 to 26 locations.

The drills were initiated in three flood zones, simulating emergencies that require the warning system to move from Grade-I to Grade-IV. Leaders of disaster relief departments were also required to enforce the implementations of responsible actions, for example they should be on duty during the disaster season, closely watching the impact on the rivers, reservoirs and flood zones.

But those are the behind the scene measures, for the common folk, trying to get from point A to point B, their concerns are with public safety features. Since 2013, the city government has been installing a safety net on sewer manholes, an action much appreciated by citizens. The net is installed under manhole covers.

To test the project, local media sources chose seven sample areas and found that Guancheng, Shilong, Shejie and Machong have accomplished the final stages. Humen, Zhongtan and Wanjiang have fallen behind. The final assessment found that, while progress is being made, there is still need for the project leaders to quicken the pace of improvement.

During the flooding, the star of the response programs was social media platforms. The Dongguan City Meteorlogical Observatory worked nonstop during the rains to release a totoal of 13 warning signals via text messages, Weibo and WeChat posts, a hotline and the official Web site to provide vital information.
Some local governments, especially that of Humen Town, were praised for their immediate media response and timely spread of information. Humentaiping, the official Weibo account of the Humen government, posted over 190 posts with updates on traffic, weather and other dynamics within the flooding 48 hours of flash flooding.